Supreme Court Chief Justice John Roberts is followed by Supreme Court Justice Antonin Scalia as they arrive for the presidential inauguration on the West Front of the U.S. Capitol in Washington January 21, 2013. REUTERS/Win McNamee/Pool

WASHINGTON (Reuters) - For an often enigmatic figure at the U.S. Supreme Court, Chief Justice John Roberts spoke to the essence of his legal philosophy on Tuesday in eliminating a voting-rights provision enacted to protect blacks and other minorities.

His opinion for the court marks the culmination of an effort by conservatives, many of whom, like Roberts, cut their teeth in the Ronald Reagan administration, to ensure that federal voting requirements on the states be limited and race-based rules fade in contemporary America.

In a tenure-defining decision, the Roberts majority undercut a key section of the 1965 Voting Rights Act that requires states with a history of racial discrimination to obtain U.S. approval before changing election laws. The court struck down the formula used to determine which states were affected. Nine mostly Southern states had been covered.

The decision was the most significant racial ruling since Roberts, 58, became chief justice in 2005. Announced on the next-to-last day of term, Shelby County v. Holder was one of the most awaited of the current session and as Roberts spoke from the bench, the hushed courtroom felt quieter than usual.

CONSERVATIVE PRIORITIES

Last year at this time, Roberts defied many people’s expectations when he provided the fifth vote to uphold the healthcare overhaul sponsored by President Barack Obama. But some legal analysts observed that such a case, testing federal commerce and taxing power, did not touch on his long-held conservative priorities.

When Roberts served as a lawyer in the Reagan administration, he sought to curtail government’s use of racial remedies and specifically narrow the reach of the Voting Rights Act. In 1982, for example, Roberts advised the president to oppose pending legislation to enhance a section aimed at intentional voter discrimination.

Roger Clegg, who worked with Roberts at the Justice Department in the 1980s, said Roberts, like other young Republican lawyers, was inspired by a broad socially conservative agenda that included such subjects as abortion, religion and race.

“These were the big-ticket items back then,” said Clegg, now president of the Center for Equal Opportunity, a conservative think tank. Clegg added that he did not think Roberts, who grew up in Indiana and was educated at Harvard, was motivated in his quest for race-neutral policies by especially Southern sympathies.

“This is not driven by the fact that his great, great grandfather was with (Confederate General Robert E.) Lee at Appomattox,” said Clegg, referring to one of the final battles of the Civil War. “It’s from his belief in federalism,” that is, a limit on what Congress may constitutionally impose on the states.

Once he joined the high court, as an appointee of Republican President George W. Bush, Roberts asserted his opposition to racial policies. In a 2006 case involving the drawing of “majority minority” voting districts to boost the political power of blacks and Latinos, Roberts referred to “this sordid business divvying us up by race.” In a 2007 dispute over school integration plans, Roberts wrote, “The way to stop discrimination on the basis of race is to stop discriminating on the basis of race.”

In a 2009 case, in which the court ultimately declined to review the constitutionality of the key Voting Rights Act section, Roberts warned that the screening provision may no longer be constitutional because “things have changed in the South.”

He questioned why Congress would still target Southern states when widespread blatant racial discrimination had ended. Can members of Congress “impose this disparate treatment forever because of the history in the South?” he asked during oral arguments in the 2009 case. “When do they have to stop?”

On Tuesday, Roberts provided an answer: Now.

In his 24-page opinion for the court, Roberts criticized Congress for leaving in place the criteria for targeted states that traced to the 1960s and early 1970s, despite the gains in voting equality since then. Voicing irritation that lawmakers had not acted on the court’s warning in 2009 to revise the formula used to determine which states were covered, Roberts said it had no choice but to strike it down.

As he wrote about the changes across the country in recent decades, the chief justice noted that voter registration rates for blacks and whites now approach parity and blatant discrimination is rare.

“Our country has changed, and while any racial discrimination in voting is too much, Congress must ensure that the legislation it passes to remedy that problem speaks to current conditions,” Roberts wrote, joined by his four fellow conservatives.

Justice Ruth Bader Ginsburg, speaking for the four liberal dissenters, said the states targeted four decades ago still had the worst voting-rights violations. She invoked the words of slain civil rights leader Martin Luther King, Jr.: “ ‘The arc of the moral universe is long, he said, but ‘it bends toward justice,’ if there is a steadfast commitment to see the task through to completion. That commitment has been disserved by today’s decision.”

In the cool marble courtroom on a scorching June morning, Roberts was expressionless. After decades of tension over the scope of voting rights, he had his majority.